1. Field of the Invention
The present invention relates to a portable information instrument, and more specifically to a portable information instrument having a display cover protecting a display screen.
2. Description of Related Art
Prior art portable information instruments includes ones which have an upper cover for protecting a display screen of a display section composed of a liquid crystal display. For example, the upper cover is joined to a body of the portable information instrument by more than one hinge, so that the upper cover can be opened and closed without being separated from the body of the portable information instrument.
In the above mentioned cover structure, in order to prevent the upper cover from being unintentionally opened, there is provided a lock mechanism for locking the upper cover into the body of the portable information instrument in the closed condition. In use, an operator manually releases the lock mechanism, and opens the upper cover to a position where the display screen of the display section is exposed, or alternatively rotates the upper cover so that the upper cover rides on a rear surface of the body of the portable information instrument.
For example, Japanese Utility Model Application Pre-examination Publication No. JP-U-63-44549 discloses a handy portable telephone having a cover hinged to a portable telephone body to be selectively latched to a first position covering an operating key section or to a second position covering a display section. Japanese Patent Application Pre-examination Publication No. JP-A-6-334778 discloses a communication terminal having a cover closed to protect an operating section and a display section and configured to automatically open the cover by means of a motor when a calling is received.
In the above mentioned prior art portable information instrument, the upper cover is hinged to the portable information instrument body by more than one hinge. However, since the upper cover has to cover the display section which occupies a large portion of an instrument front surface area, the upper cover interferes with operation of the portable information instrument, or makes it instable to hold the portable information instrument by a hand, or becomes hindrance to start to use the portable information instrument in a congested condition.
Furthermore, in the case that when the upper cover is opened the cover is rotated to the rear surface of the portable information instrument body, a space larger than the portable information instrument body is temporarily occupied by the opening and closing of the cover, resulting in hindrance to start to use the portable information instrument in the congested condition.
Furthermore, when the portable information instrument has the lock mechanism for locking the upper cover into the body of the portable information instrument in the closed condition, it is necessary that, in order to view the display section, the operator manually releases the lock mechanism by his hand each time so as to open the cover. Therefore, even if an alarm for a schedular is set in the portable information instrument, when the alarm is sounded, the operator cannot immediately known or confirm the content of the alarm.
Still further, in the portable information instrument having the cover to be automatically opened by means of a motor, it is a general practice to supply an electric power to the motor from a battery cell of the portable information instrument. On the other hand, for miniaturization and the weight-reducing of the portable information instrument, an enough battery cell capacity cannot be ensured. Therefore, if it is attempted to open the cover by the motor, the electric power is wastefully consumed by the operation of the motor, so that the battery cell capacity which can be used by the portable information instrument itself is correspondingly reduced.